Deleting images from events

How can I delete images from events? (or any other collateral material, for that matter)

I created two timelines and then convinced my publisher to embed them in a recent story I wrote for PR News Online: http://www.prnewsonline.com/news/tops... (url may break in a few days)

I noticed a problem in one of them: http://www.dipity.com/user/shabbir/ti...

Once I add an image, there's no way to drop the image without deleting the event and recreating it! I added an image that inconsistently displays and I have to delete the whole event to fix it.